Faculty Bibliography

BACKGROUND AND PURPOSE/OBJECTIVE:There are limited data on predictors of 30-day stroke or death in patients with symptomatic intracranial atherosclerosis (sICAS) undergoing stenting. We aim to determine the factors associated with stroke or death at 30 days in the stenting arm of the SAMMPRIS trial. METHODS:This is a post-hoc analysis of the SAMMPRIS trial including patients who underwent angioplasty/stenting. We compared patient-specific variables, lesion-specific variables, procedure-specific variables, and FDA-approved indications between patients with and without the primary outcome (stroke or death at 30 days). Logistic regression analyses were performed to evaluate associations with the primary outcome. RESULTS:We identified 213 patients, 30 of whom (14.1%) met the primary outcome. Smoking status and lesion length were associated with the primary outcome: the odds of stroke or death for non-smokers versus smokers (adjusted OR 4.46, 95% CI 1.79 to 11.1, p=0.001) and for increasing lesion length in millimeters (adjusted OR 1.20, 95% CI 1.02 to 1.39, p=0.029). These had a modest predictive value: absence of smoking history (sensitivity 66.7%, specificity 65.4%) and lesion length (area under curve 0.606). Furthermore, event rates were not significantly different between patients with and without the FDA-approved indication for stenting (15.9% vs 12%, p=0.437). CONCLUSION/CONCLUSIONS:In SAMMPRIS patients who underwent angioplasty/stenting, neither clinical and neuroimaging variables nor the FDA indication for stenting reliably predicted the primary outcome. Further work in identifying reliable biomarkers of stroke/death in patients with sICAS is needed before considering new clinical trials of stenting. TRIAL REGISTRATION NUMBER/BACKGROUND:SAMMPRIS NCT00576693; Results.

Purpose of Study Autism spectrum disorders (ASDs) are neurodevelopmental disorders with lifelong consequences and poorly understood pathophysiology. Dysregulated cholesterol metabolism is implicated in ASD etiology. Cholesterol is essential for neuroactive steroid production, myelin sheath formation, and normal brain development. Early postnatal or in utero exposure to the antiepileptic drug valproic acid (VPA), a branched short-chain fatty acid, causes autism-like neural and behavioral deficits in humans and rodents. This study examines the link between VPA and cholesterol deficit in cultured human neurons and microglia. Methods Used SHSY-5Y human neuroblastoma cells and HMC3 human microglial cells were exposed to VPA at 0, 250, 1000 and 5000 muM for 24h, N=3 per condition. Expression of critical genes that regulate cholesterol transport were quantified by RT-PCR using specific primers for each. These include the efflux proteins ABCA1, ABCG1, 27-hydroxylase (27-OHase) and 24-hydroxylase (24-OHase), and the influx scavenger receptor CD36 - all vital for brain cholesterol balance. Expression of these target genes was normalized to concurrently measured GAPDH mRNA levels. Summary of Results In SH-SY5Y neurons, VPA exposure caused a concentration-dependent increase in ABCA1 (P <0.001), ABCG1, 27-OHase (P <0.001) (figure 1), and CD36 (P=0.015). In HMC3, VPA exposure caused a concentration- dependent increase in ABCG1 (80-fold at highest dose, P<=0.001) and 24-OHase (P < 0.001) with a reduction in ABCA-1 (P=0.002) and an increase in CD36 (P<0.001). Conclusions This study shows that VPA has a dramatic hypocholesterolemic effect on two key cell types that compose the developing brain. The net impact of the changes observed in these cholesterol-related genes would be outflow and metabolism. Further, enhanced 27-OHase activity produces an oxysterol metabolite with neurotoxic effects that include downregulating synaptic proteins and decreasing neurite number and length. Together, our results suggest that VPA impairs brain cholesterol homeostasis. A better understanding of the involvement of cholesterol in the mechanisms by which VPA leads to ASDs may translate into novel preventative therapies for this serious disorder

BACKGROUND AND PURPOSE/OBJECTIVE:Acute rehabilitation is known to enhance stroke recovery. However, poststroke lethargy and fatigue can hinder participation in rehabilitation therapies. We hypothesized that in patients with moderate to severe stroke complicated by poststroke fatigue and lethargy early stimulant therapy with modafinil increases favorable discharge disposition defined as transfer to acute inpatient rehabilitation or home. METHODS:We retrospectively reviewed a cohort of patients with acute stroke admitted to the stroke service over a 3-year period. All patients 18 years or older with confirmed ischemic or hemorrhagic stroke, an NIHSS greater than or equal to 5 and documentation of fatigue/lethargy in clinical documentation were included. We compared patients that were treated with modafinil 50-200 mg to those managed with standard care. The primary outcome measure was discharge disposition. Secondary outcome was 90 day modified Rankin score (mRS). Statistical significance was determined using chi-square test for association and logistic regression models. Logistic regression models were derived in 2 ways with both raw data and an adjusted model that accounted for age, sex, and NIHSS score to account for the lack of randomization. RESULTS:This study included 199 stroke patients (145 ischemic, 54 hemorrhagic). Seventy-two (36.2%) were treated with modafinil and 129 (64.8%) were discharged to acute inpatient rehabilitation, while none were recommended for discharge home. Median NIHSS for modafinil patients was 13.5 versus 11 for standard care patients (P = .059). In adjusted models, modafinil was associated with higher odds of favorable discharge disposition (OR 2.00, 95% CI 1.01-3.95). Favorable outcome at 90 days defined as mRS less than or equal to 2 occurred more frequently with modafinil (5.6% versus 3.3%) but this did not achieve statistical significance (P > .1). These results occurred despite the modafinil group requiring longer ICU stays and having more in-hospital complications such as infections and need for percutaneous gastrostomy tubes. The benefit of modafinil was seen across all subgroups except those with severe stroke (NIHSS ≥ 15). There were no significant adverse events associated with modafinil administration. CONCLUSIONS:Modafinil use in acute in-hospital stroke patients with moderate stroke complicated by lethargy and fatigue was associated with improved discharge disposition. Randomized controlled trials are needed to further study the safety, efficacy, and long-term effects of modafinil in this patient population.

Mutations in GBA1, the gene mutated in Gaucher disease, are a common genetic risk factor for Parkinson disease, although the penetrance is low. We performed [¹⁸ F]-Fluorodopa PET studies of 57 homozygous and heterozygous GBA1 mutation carriers (15 with parkinsonism) and 98 controls looking for early indications of dopamine loss using voxel-wise analyses to identify group differences in striatal [¹⁸ F]-Fluorodopa uptake (K_i ). Forty-eight subjects were followed longitudinally. Cross-sectional and longitudinal comparisons of K_i and K_i -change found significant effects of Parkinson disease. However, at baseline and over time, striatal [¹⁸ F]-Fluorodopa uptake in mutation carriers without parkinsonism did not significantly differ from controls. This article is protected by copyright. All rights reserved.

Williams syndrome (WS) is a rare neurodevelopmental disorder caused by the hemideletion of approximately 25-28 genes at 7q11.23. Its unusual social and cognitive phenotype is most strikingly characterized by the disinhibition of social behavior, in addition to reduced global IQ, with a relative sparing of language ability. Hypersociality and increased social approach behavior in WS may represent a unique inability to inhibit responses to specific social stimuli, which is likely associated with abnormalities of frontostriatal circuitry. The striatum is characterized by a diversity of interneuron subtypes, including inhibitory parvalbumin-positive interneurons (PV+) and excitatory cholinergic interneurons (Ch+). Animal model research has identified an important role for these specialized cells in regulating social approach behavior. Previous research in humans identified a depletion of interneuron subtypes associated with neuropsychiatric disorders. Here, we examined the density of PV+ and Ch+ interneurons in the striatum of 13 WS and neurotypical (NT) subjects. We found a significant reduction in the density of Ch+ interneurons in the medial caudate nucleus and nucleus accumbens, important regions receiving cortical afferents from the orbitofrontal and ventromedial prefrontal cortex, and circuitry involved in language and reward systems. No significant difference in the distribution of PV+ interneurons was found. The pattern of decreased Ch+ interneuron densities in WS differs from patterns of interneuron depletion found in other disorders.

Biochirality is the subject of distinct branches of science, including biophysics, biochemistry, the stereochemistry of protein folding, neuroscience, brain functional laterality and bioinformatics. At the protein level, biochirality is closely associated with various post-translational modifications (PTMs) accompanied by the non-equilibrium phase transitions (PhTs ^NE). PTMs ^NE support the dynamic balance of the prevalent chirality of enzymes and their substrates. The stereoselective nature of most biochemical reactions is evident in the enzymatic (Enz) and spontaneous (Sp) PTMs (PTMs ^Enz and PTMs ^Sp) of proteins. Protein chirality, which embraces biophysics and biochemistry, is a subject of this review. In this broad field, we focus attention to the amyloid-beta (Aβ) peptide, known for its essential cellular functions and associations with neuropathology. The widely discussed amyloid cascade hypothesis (ACH) of Alzheimer's disease (AD) states that disease pathogenesis is initiated by the oligomerization and subsequent aggregation of the Aβ peptide into plaques. The racemization-induced aggregation of protein and RNA have been extensively studied in the search for the contribution of spontaneous stochastic stereo-specific mechanisms that are common for both kinds of biomolecules. The failure of numerous Aβ drug-targeting therapies requires the reconsolidation of the ACH with the concept of PTMs ^Sp. The progress in methods of chiral discrimination can help overcome previous limitations in the understanding of AD pathogenesis. The primary target of attention becomes the network of stereospecific PTMs that affect the aggregation of many pathogenic agents, including Aβ. Extensive recent experimental results describe the truncated, isomerized and racemized forms of Aβ and the interplay between enzymatic and PTMs ^Sp. Currently, accumulated data suggest that non-enzymatic PTMs ^Sp occur in parallel to an existing metabolic network of enzymatic pathways, meaning that the presence and activity of enzymes does not prevent non-enzymatic reactions from occurring. PTMs ^Sp impact the functions of many proteins and peptides, including Aβ. This is in logical agreement with the silently accepted racemization hypothesis of protein aggregation (RHPA). Therefore, the ACH of AD should be complemented by the concept of PTMs ^Sp and RHPA.

Pathophysiological understanding of gait and balance disorders in Parkinson's disease is insufficient and late recognition of fall risk limits efficacious follow-up to prevent or delay falls. We show a distinctive reduction of glucose metabolism in the left posterior parietal cortex, with increased metabolic activity in the cerebellum, in parkinsonian patients 6-8 months before their first fall episode. Falls in Parkinson's disease may arise from altered cortical processing of body spatial orientation, possibly predicted by abnormal cortical metabolism.

OBJECTIVE:R) in surgical tissue from patients with temporal lobe epilepsy and hippocampal sclerosis (TLE/HS) with SUDEP risk factors. METHODS:R in seven regions of interest: temporal cortex, temporal lobe white matter, CA1, CA4, dentate gyrus, subiculum, and amygdala and relative to glial and neuronal densities with glial fibrillary acidic protein (GFAP) and neuronal nuclear antigen (NeuN). RESULTS:R was present in the amygdala in high-risk than in low-risk cases. There was no significant difference in neuronal loss or gliosis between the risk groups or differences for ADK labeling. SIGNIFICANCE/CONCLUSIONS:R in the high-risk group could contribute to periictal amygdala dysfunction in SUDEP.

OBJECTIVE:Survivors of prolonged (> 2 weeks) post-cardiac arrest (CA) coma are expected to remain permanently disabled. We aimed to investigate three outlier patients who ultimately achieved independent functional outcomes after prolonged post-CA coma to identify electroencephalographic (EEG) markers of their recovery potential. For validation purposes, we also aimed to evaluate these markers in an independent cohort of post-CA patients. METHODS:We identified three patients with late recovery from coma (17-37 days) following CA who recovered to functionally independent behavioral levels. We performed spectral power analyses of available EEGs during prominent burst suppression patterns (BSP) present in all three patients. Using identical methods, we also assessed the relationship of intra-burst spectral power and outcomes in a prospectively enrolled cohort of post-CA patients. We performed chart reviews of common clinical, imaging, EEG prognostic variables and clinical outcomes for all patients. RESULTS:All three patients with late recovery from coma lacked evidence of overwhelming cortical injury but demonstrated prominent BSP on EEG. Spectral analyses revealed a prominent theta (~4-7Hz) feature dominating the bursts during BSP in these patients. In the prospective cohort, similar intra-burst theta spectral features were evident in patients with favorable outcomes; patients with BSP and unfavorable outcomes showed either no features, transient burst features or decreasing intra-burst frequencies with time. INTERPRETATION/CONCLUSIONS:BSP with theta (~4-7Hz) peak intra-burst spectral power after CA may index a recovery potential. We discuss our results in the context of optimizing metabolic substrate availability and stimulating the cortico-thalamic system during recovery from prolonged post-CA coma. This article is protected by copyright. All rights reserved.

BACKGROUND:Following the results of randomized clinical trials supporting the use of mechanical thrombectomy (MT) with tissue plasminogen activator for emergent large vessel occlusion (ELVO), our state Stroke Task Force convened to: update legislation to recognize differences between Primary Stroke Centers (PSCs) and Comprehensive Stroke Centers (CSCs); and update Emergency Medical Services (EMS) protocols to triage direct transport of suspected ELVO patients to CSCs. PURPOSE/OBJECTIVE:We developed a single-session training curriculum for EMS personnel focused on the Los Angeles Motor Scale (LAMS) score, its use to correctly triage patients as CSC-appropriate in the field, and our state-wide EMS stroke protocol. We assessed the effect of our training on EMS knowledge. METHODS:We assembled a focus group to develop a training curriculum and assessment questions that would mimic real-life conditions under which EMS personnel operate. Ten questions were formulated to assess content knowledge before and after training, and scores were compared using generalized mixed models. RESULTS:Training was provided for 179 EMS providers throughout the state.Average pre-test score was 52.4% (95% CI 49% to 56%). Average post-test score was 85.6% (83%-88%, P<0.0001). Each of the 10 questions was individually assessed and all showed significant gains in EMS knowledge after training (P<0.0001). CONCLUSIONS:A brief educational intervention results in substantial improvements in EMS knowledge of prehospital stroke severity scales and severity-based field triage protocols. Further study is needed to establish whether these gains in knowledge result in improved real-world performance.